Electric motor



0. LINDELL ELECTRIC MOTOR June 27, 1939.

Filed Feb. 23, 1938 24 myrawwza ATTORN EYS Patented June 27, 1939 UNITED STATES PATENT OFFICE 2,164,250 ELECTRIC MOTOR Oliver Lindell, Shawnee, Okla.

Application February 23,

3 Claims.

motor, No. 2,112,852, dated April 5, 1938.

An object of the advantages of the invention.

In the accompanying drawing forming part of this specification,

Figure 1 is a fragmentary longitudinal sectional view of an electric motor having magnet contacts constructed in accordance with the invention.

Figure 2 is a perspective view of certain of the magnet contacts shown in Figure 1.

Figure 3 is a perspective view of three contiguous magnet contacts.

Figure 4 is a front elevation showing a plurality of modified magnet contacts.

Figure 5 is a perspective View of two contiguous magnet contacts of the modified form shown in Figure 4.

Figure 6 is a wiring diagram showing each magnet shunting contact bridging a plurality of magnet contacts.

Referring now to the drawing in which like characters of reference designate similar parts a series of 1938, Serial N0. 192,147

drical core member 9. A hollow cylindrical casing I4 is splined upon the rotor shaft and houses a spring l8 which is tensioned by a nut l6 screw threadedly engaged with the shaft.

A dished annular supporting plate. I9 is rigidly fixed to the stator and fixed to the plate is a magnet contact retaining plate 20 of channel connovel forming the subject matter which will be later described in detail. The nuvolves as a unit with the rotor. Tension of the spring l8 holds the magnet shunting contacts 29 in tight rubbing contact with the magnet contacts 23.

With the exception of the magnet contacts 23 the above described parts closed in my above identified patent applicamagnet contacts 23, as best shown in What is claimed is:

1. In an electric motor of the class described, an annular series of magnet shunting contacts, an annular series of magnet contacts opposite the shunting contacts, magnet lead wires connected to the magnet contacts, the magnet shunting contacts being adaptedto bridge a plurality of the magnet contacts simultaneously, and lugs projecting from the magnet contacts having Wiping engagement with the shunting contacts and arranged in stepped relation to provide air gaps between the lugs.

2. The combination with a motor in which magnet coils are arranged in groups of a plurality of coils, of an annular series of magne't'shunting contacts, an annular series of magnet contacts, leads from said coils connected to respective ones of said magnet contacts, and lugs projecting from said magnet contacts and adapted to have wiping engagement with said shunting V circumferential radial direction vent arcing, said contacts, the lugs of the magnet contacts of each group of magnet coils being arranged in stepped relation with respect to each other in a radial direction and being spaced from each other in a direction to provide air gaps for preventing arcing.

3. In an electric motor, a stationary annular series of magnet shunting contacts, a rotatable annular series of magnet contacts, and lugs on the magnet contacts having wiping engagement with the shunting contacts, each lug being spaced from the next adjacent lug to provide air spaces in a circumferential direction and in a between adjoining lugs to prelugs having extensions of substantially triangular contour, the extensions of contiguous'contacts having their apices reversed in direction with respect to each other.

OLIVER LINDELL. 

